Question

You carry a 7.0-kg bag of groceries 1.2 m above the ground at constant speed across a 2.7m room. How much work do you do on the bag in the process? (A) 157J (B) 0.00J (C) 185J (D) 82J

Answer 1

Answer:

Work done, W = 0 J

Explanation:

It is given that,

Mass of the bag, m = 7 kg

If a person carries a bag of groceries 1.2 m above the ground at constant speed across a 2.7 m room. We need to find the amount of work done on the bag he the process. It is given by :

$W=Fd\ cos\theta$

Where

θ = angle between the force and the direction of motion. Here, θ = 90° (its weight is acting vertically downward and it is moving forward)

Since, cos(90) = 0

⇒ Work done, W = 0 J

So, the work done on the bag is zero. Hence, the correct option is (b) "0 J".